A. _Eyelid Tics._--These, perhaps the commonest of all tics, may be either unilateral or bilateral. They consist simply in a palpitation of the upper lid, repeated at irregular intervals, and differing from ordinary blinking only in augmented frequency and abruptness. The form they usually assume is that of a wink, attributable in the first instance to contraction of the orbicularis, but supplemented by the zygomatics and muscles of the nose. The tonic variety of the same tic is constituted by a contraction of inordinate length, the outcome of which is the all but permanent maintenance of the eye in a half-closed position. The suspension of this tonic tic by volitional effort accentuates its distinction from contracture. In one of our patients a tic of this nature, which gave a singularly sleepy cast to the features, was easily relieved by suitable gymnastic treatment. The converse condition obtained in another case, where excessive gaping of the palpebral fissure contributed an unwonted fixity to the expression, which simultaneous contraction of the corrugator supercilii served to heighten into one of wild anger. These two tics corresponded to two diametrically opposed traits in their subject's character--viz. nonchalance and impatience respectively, and it is interesting to recall in this connection how the varying moods depend for their physiognomical delineation chiefly on the degree of curvature of the palpebral arc. Valleix,[64] who employed the term "idiopathic facial convulsion" to designate tic, cites a case where even in moments of tranquillity the left eye seemed slightly smaller than its fellow, by reason of a feeble contraction of the orbicularis. Persistent grimaces of this kind resemble tics of attitude and stereotyped acts, and the possibility of their occurrence must not be overlooked, once the diagnosis of facial paralysis or spasm has been rigorously excluded. The terms blepharospasm and blepharoclonus, sometimes applied to tonic and to clonic involuntary palpebral contractions respectively, ought to be strictly reserved for spasms and contractures properly so called. For example, von Graefe's case of blindness consequent on permanent closure of the eyelids in a child is undoubtedly one of blepharospasm. No tic could have been attended with such a result, whereas compression of branches of the trigeminal at their points of exit might determine reflex tonic contraction of the orbicularis, and so, for that matter, might a central lesion. Hence in these circumstances it is correct to use the word spasm. Palpebral tics are among those that ordinarily begin by a spasmodic reaction to an extraneous source of irritation, such as that yielded by a foreign body, a speck of dust, an eyelash, or by any form of conjunctival inflammation.